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ARS Home » Midwest Area » Columbia, Missouri » Plant Genetics Research » Research » Publications at this Location » Publication #381572

Research Project: Soybean Seed Improvement Through Translational Genomics, Assessments of Elemental Carbon Metabolism, and Lipid Profiles

Location: Plant Genetics Research

Title: Analyzing mass spectrometry imaging data of 13C-labeled phospholipids in camelina sativa and thlaspi arvense (pennycress) embryos

item ROMSDAHL, TREVOR - University Of North Texas
item KAMBHAMPATI, SHIRKAAR - Danforth Plant Science Center
item KOLEY, SOMNATH - Danforth Plant Science Center
item YADAV, UMESH - University Of North Texas
item ALONSO, ANA - University Of North Texas
item Allen, Douglas - Doug
item CHAPMAN, KENT - University Of North Texas

Submitted to: Metabolites
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/2/2021
Publication Date: 3/4/2021
Citation: Romsdahl, T.B., Kambhampati, S., Koley, S., Yadav, U.P., Alonso, A.P., Allen, D.K., Chapman, K.D. 2021. Analyzing mass spectrometry imaging data of 13C-labeled phospholipids in camelina sativa and thlaspi arvense (pennycress) embryos. Metabolites. 11(3). Article e148.

Interpretive Summary: One of the keys to improving productivity of crops is to better understand cellular metabolism that helps establish the observed plant phenotype. However the interconversion of metabolites can vary within a tissue, therefore methods and approaches that can assess metabolic features spatially are important. In this study imaging based mass spectrometry was used to assess metabolites in plant tissues. The production of lipids, that can be an important source of biofuel, were probed through isotopic tracers. Then the amount of tracer in different metabolites was determined through the mass spectrometry approaches. The studies indicated important differences in lipid metabolism in different parts of the seed that result in differences in fatty acid profile. As the composition of fatty acids in oilseeds establish the quality of vegetable oil for human nutrition and also contribute to the value of a biofuel, the workflow and approach described is an important strategy to glean information that can aid crop design for human needs.

Technical Abstract: The combination of 13C-isotopic labeling and mass spectrometry imaging (MSI) offers an approach to analyze metabolic flux in situ. However, combining isotopic labeling and MSI presents technical challenges ranging from sample preparation, label incorporation, and data collection and analysis. Isotopic labeling and MSI each create large, complex data sets, and this is compounded when both methods are combined. Therefore, analyzing isotopically labeled MS imaging data requires streamlined procedures to support biologically meaningful interpretations. Using currently available software and techniques, here we describe a workflow to analyze 13C-labeled isotopomers of the membrane lipid and storage oil lipid intermediate-- phosphatidylcholine (PC). Our results with embryos of the oilseed crops, Camelina sativa and Thlaspi arvense (Pennycress), demonstrated greater 13C-isotopic labeling in the cotyledons of developing embryos compared with the embryonic axis. Greater isotopic enrichment in PC molecular species with more saturated and longer chain fatty acids suggest different flux patterns related to fatty acid desaturation and elongation pathways. The ability to evaluate MSI data of isotopically labeled plant embryos will facilitate the potential to investigate spatial aspects of metabolic flux in situ.